As a rule, acuracy does not depend on the calober but on the rifle itself. Rifles with lower recoil levels however for most would be more shootable. I have owned some super accurate rifles. Probably the most accurate were a 270, a 6.5x55 and a 257 Roberts.

Tack driver is differentt things to different people. To me a tack driver will shoot one inch or less @ 200 yards.